JPH01245913A - Manufacture of composite wire - Google Patents

Abstract

PURPOSE:To reduce the cost of a product and to improve the quality of the product by coating a brushing worked copper tape on a fellonickel alloy wire, after welding the copper tape in the state of specified partial pressure of oxygen and performing a cold wire drawing in a specified condition through a conical die. CONSTITUTION:The Fe-Ni alloy wire 1 in a feeding reel 4 is swept by a brush ing apparatus 6 to purify the surface, then introduced into a forming part 10 of a pipe manufacturing apparatus. The Cu tape 2 in the feeding reel 7 is subjected to brushing and after a rough surface working is performed on one surface, it is fed into the forming part to be rounded into the alloy wire 1 to coat and to form. Then, the end part of the Cu tape 2 is welded by a TIG welder 12 in the atmosphere of the partial pressure under 0.01atm of oxygen. Subsequently, the cold wire drawing is performed through the conical die 20 having the die angle 2alpha by 4-30 deg. to obtain the composite wire. Because the Cu coating and wire drawing stages are performed continuously, the manufactur ing cost is reduced and because no intermediate phase is interposed, the product quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a composite wire suitable for a Dumet wire used in glass-enclosed parts of electron tubes, light bulbs, discharge lamps, semiconductor devices, etc.

[Prior Art] Encapsulated lead wire materials used in glass encapsulated parts of semiconductor devices, etc. have good wettability and adhesion with glass, and have a coefficient of thermal expansion similar to that of glass at the temperature during glass sealing and use. It is also required to have good malleability and mechanical workability. Dumet wire has long been used as a lead wire material for such glass-enclosed parts.

The Dumet wire is constructed by coating a core material made of an iron (Fe)-nickel (Ni) alloy with copper (Cu) at a coverage rate of about 20%. In this case, Cu and Fe-N
If the bonding between the Fe-Ni alloy and the Fe-Ni alloy is not sufficient, peeling will occur during the sealing process to the diode, which will impair the airtightness. It is necessary to join them.

For this reason, this Dumet wire has conventionally been manufactured by the method shown below. First, in the first method,
A Fe-Ni alloy core wire is inserted into a Cu tube and heated to 850 to 900°C in a neutral or reducing air flow to reduce the temperature by 12 to 16%.
It is manufactured by joining the Fe-Ni core wire and the Cu tube by hot rolling with a cross-sectional shrinkage rate of , may also be hot pressed.

In addition, after plating zinc (Zn) on the Fe-Ni alloy core wire or winding a brass tape, it is coated with a Cu tape, and after diffusion heat treatment, the zero-order method is used to join Cu and Fe-Ni alloy. , Dumet wire is manufactured by wire drawing.

Furthermore, a method of manufacturing a Cu-coated Fe-N1p gold wire by plating Cu on a Fe-Ni alloy core wire is also described.

[Problems to be solved by the invention] However, in these conventional manufacturing methods,
There are drawbacks as shown below.

First, in the method of hot working or hot pressing after coating the Cu tube, there is a hot machining or hot pressing process, so it is not possible to manufacture a composite wire in a continuous process. Manufacturing costs are high.

In addition, in order to reduce manufacturing costs as much as possible, a large diameter core wire is used as the starting material, but it is necessary to draw the wire in an extremely large number of buses before it is processed into a thin wire of the final diameter. Since the degree of processing is large, it is necessary to perform an annealing treatment during the process.

Furthermore, variations in hot working conditions, hot pressing conditions, etc. tend to cause uneven bonding strength.

On the other hand, in a method in which a Fe-Ni alloy core wire is coated with Cu with Zn or brass interposed therebetween and then subjected to diffusion heat treatment,
Since it is difficult to make the thickness of the intermediate layer such as Zn uniform, characteristics such as residual strain and linear expansion change in the circumferential direction. For this reason, Cu may peel off from the Fe-Ni alloy core wire. In addition, this method involves complicated steps, resulting in high manufacturing costs.

Furthermore, in the method of plating Cu on a Fe-Ni alloy core wire, the Cu coating layer to be formed is significantly thicker than a normal plating layer, so it is necessary to conduct the plating treatment for a long time. For this reason, manufacturing costs are similarly high.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide a method for manufacturing a composite wire, which enables continuous processes, low manufacturing costs, and can manufacture a high-quality composite wire without local variations in characteristics.

[Means for Solving the Problems] The method for manufacturing a composite wire according to the present invention includes a step of brushing one side of a copper tape and an iron-nickel alloy wire, and a step of bringing the brushed surface into contact with an iron-nickel alloy wire to remove the copper. a step of coating and forming the tape on the iron-nickel alloy wire; a step of welding the ends of the copper tape in an atmosphere with an oxygen partial pressure of 0.01 atmosphere or less to obtain a copper-coated iron-nickel alloy wire; The die angle 2α of coated iron-nickel alloy wire is 4 to 30.
The method is characterized by comprising a step of cold wire drawing with a degree of working of 75% or more using a conical die.

[Function] In order to reduce manufacturing costs, it is necessary to eliminate the batch process and complete the bonding only by cold working, and it is better to avoid the presence of an intermediate layer because it causes many quality problems. The present invention has been completed from this perspective.

That is, in the present invention, a brushed Cu tape is coated on a Fe-Ni alloy wire with its brushed surface in contact with the Fe-Ni alloy wire, and the edges of the Cu tape are welded in an atmosphere with an oxygen partial pressure of 0.01 atmosphere or less. (Cu coating step).

By cold drawing this composite wire at a processing degree of 75% or more using a conical die with a die angle 2α of 4 to 30'', the Cu layer and the Fe-Ni alloy core wire are metallically bonded (
wire drawing process).

As described above, in the present invention, the manufacturing process is roughly divided into the Cu coating process and the wire drawing process, and each process is made continuous, thereby reducing processing costs and manufacturing costs.

In addition, since there is no intermediate layer between the Cu layer and the Fe-Ni alloy core wire, there is no variation in properties in the circumferential direction, making it possible to manufacture high-quality composite wires, as well as surface treatment in the post-process. Even if heated to 900° C. or higher in the process, since there is no intermediate layer, there is no risk of swelling caused by melting or the like.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the process of obtaining a composite line in the embodiment method of the present invention. A Fe-Ni alloy wire 1 is wound around the delivery reel 4, and the delivery reel 4 rotates to feed Fe-Ni alloy wire 1.
-Ni alloy wire 1 is sent out. After this Fe-Ni alloy wire 1 is straightened into a straight line through a strainer 5, it is supplied to a brushing device 6, and within this brushing device 6,
For example, the surface is cleaned by sweeping with a stainless steel brush. Next, this Fe--Ni alloy wire 1 is supplied to a forming section 10 of a tube-making apparatus 9.

The Cu tape 2 is wound around the Cu tape delivery reel 7 , and the Cu tape 2 unwound from the delivery reel 7 is fed to the brushing device 8 . In this brushing device 8, the upper surface of the Cu tape 2 is swept by, for example, a brush made of stainless steel, and fine scratches are added to the surface to give it a rough surface condition. After that, this Cu
The tape 2 is supplied to a forming section 10 of a tape tube making apparatus 9.

In the forming section 10, the brushed upper surface of the Cu tape 2 is brought into contact with the surface of the Fe-Ni alloy wire 1, and the Cu tape 2 is rolled into a cylindrical shape with its longitudinal direction serving as the axis. A Cu tape 2 is coated around the Ni alloy wire 1. In this way, the Cu tape 2 is
After being longitudinally attached to the -Ni alloy wire 1, the mating ends of the Cu tape 2 are TTG welded using, for example, a TIG welding machine 12.

In this case, the Fe--Ni alloy wire 1 and the Cu tape 2 after brushing are shielded from the outside air with N2 gas to prevent their oxidation. As a result, the Fe-Ni alloy wire 1 whose surface has been cleaned by brushing and the Cu tape 2 whose surface has been roughened and made to have fine irregularities by brushing can be bonded together without an oxide layer intervening on their surfaces. They come into contact and are easily joined together in the cold wire drawing process in the subsequent process.

In addition, when welding the butt ends of Cu tape, the oxygen partial pressure of the atmosphere should be set to 0.01 atm or less, and F
Prevents oxidation of the e-Ni alloy wire 1 and Cu tape 2.

The reason for setting the oxygen partial pressure to 0.01 atm or less is that if it exceeds this, the Cu tape 2 will oxidize during welding, and the Fe-Ni alloy wire 1 will oxidize.
This is because the bonding strength between and the Cu tape 2 decreases.

As a result, a C, u-coated Fe-Ni alloy wire 3 is obtained in which the Fe-Ni alloy wire 1 is used as a core material and the periphery of the core material is covered with a Cu coating layer. This wire 3 is wound onto a take-up reel 13.

Next, this Cu-coated Fe--Ni alloy wire 3 is wire-drawn using a conical die 20 shown in FIG. This conical die 20 has a conical inner surface, and is divided into a bell section 21, an approach section 22, a bearing section 23, and a relief section 24 depending on the difference in the cone center angle of this inner surface. The die 20 has a die angle 2α determined by the boundary between the approach portion 22 and the bearing portion 23 of 4 to 3.
0". By passing the Cu-coated Fe--Ni alloy wire 3 through this die 20 once or multiple times, the Dumet wire is produced by cold drawing at a workability of 75% or more.

The reason why the die angle 2α is set to 4° or more is because if 2α is not grooved by 4°, productivity will decrease and the Cu coating layer will peel off during wire drawing. Also, the die angle 2α
If the angle exceeds 30°, defects such as wrinkles will occur in the Cu coating layer. For this reason, the die angle 2α is set to 4 to 30°.

In addition, by adding such large processing, we were able to increase the processing degree of cold wire drawing to over 75%.
This is because the alloy wire and the Cu coating layer covering the Fe--Ni alloy wire are joined and metallically bonded without intervening an intermediate layer.

In this way, Z is formed between the Cu layer and the Fe-Ni alloy wire.
without intervening an intermediate layer such as n or brass (Cu layer and F
Since the e-Ni alloy wire can be joined, there is no variation in properties in the circumferential direction of the wire, and a high-quality composite wire can be obtained. In addition, even if heated to 900° C. or higher in the subsequent surface treatment step, there is no risk of defects such as blistering caused by melting of the intermediate layer.

Further, as described above, the Cu coating step and the wire drawing step are each a series of continuous steps, so manufacturing costs are reduced.

Next, the results of actually manufacturing a composite wire using the example method of the present invention will be explained.

Fe-Ni alloy wire containing 42% by weight of Ni (diameter 7
．． 0 mm) and an oxygen-free copper tape (thickness: 0.5 mm), the Cu tape was roll-formed using the apparatus shown in FIG. 1 and coated on the Fe--Ni alloy wire. Then, by TIG welding the ends of the Cu tape, the Cu-coated Fe-Ni
An alloy wire was obtained.

The Cu-coated Fe-Ni alloy wire rod (about 900 m in length) produced through this series of steps was passed through a continuous wire drawing machine equipped with a conical die shown in Figure 2 three times to reduce the diameter to 1.
．． Cold wire drawing was carried out until it reached 01111. The die angle 2α of the die was 15°, and the area reduction rate per bath was 8% on average.

The Dumet wire thus obtained was subjected to a crush test to evaluate bondability. This crushing test was carried out with a total load of 5 tons on a test material with an end face of 30 rm in length, and the cross section of the test material after crushing was examined with a microscope at approximately 10 to 30 cm.
By observing with 0x magnification, the Cu layer and Fe-4
The bondability of the interface with the 2% Ni alloy wire portion was evaluated. As a result of this evaluation, in the case where the working degree in cold wire drawing was 70%, a gap was observed between the copper and the core material with the naked eye. On the other hand, when the processing degree is 80% (wire with a diameter of 3.1 mm), it is recognized that the two are joined to some extent, and when the processing degree is 85% (wire with a diameter of 2.8 mm) is Cu
and the Fe-Ni alloy were completely integrated.

[Effects of the Invention] According to the present invention, the Cu coating step and the wire drawing step are each a series of steps, and by making the steps continuous, the processing cost is significantly reduced, and the manufacturing cost is extremely reduced.

Furthermore, Zn or N is present between Cu and the Fe-Ni alloy core wire.
Since an intermediate layer (third phase) such as i-plating is not used, there is no variation in characteristics in the wire layer direction due to the third phase, so a high quality composite wire can be manufactured.

Furthermore, since there is no third phase, even if heat treatment is performed in a post-process, no blisters or the like will occur at the interface due to melting of the third phase.

Furthermore, since it can be manufactured in a continuous process, it is easy to maintain a high quality level.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an apparatus used in the Cu coating process of the embodiment method of the present invention, and FIG. 2 is a longitudinal sectional view showing a conical die similarly used in the wire drawing process. 1; Fe-Ni alloy wire, 2; Cu tape, 3; Cu-coated Fe-Ni alloy wire, 6, 8; brushing device, 9; tube making device, 10; forming section, 20; conical die Fig. 2

Claims (1)

[Claims] (1) A step of brushing one side of the copper tape and the iron-nickel alloy wire, a step of bringing the brushed surface into contact with the iron-nickel alloy wire to cover and mold the copper tape over the iron-nickel alloy wire, and the copper tape A step of welding the ends of the wire in an atmosphere with an oxygen partial pressure of 0.01 atm or less to obtain a copper-coated iron-nickel alloy wire, and a step of cutting the copper-coated iron-nickel alloy wire into a conical die with a die angle 2α of 4 to 30 degrees. 75% by
A method for manufacturing a composite wire, comprising the step of cold drawing at a working degree of above.